A distributed control architecture is a state-of-the-art control architecture for use in an ESS(Electronic Switching System), wherein a number of processors performing a variety of functions are involved and practical and useful cooperations between the processors are achieved by using a so-called IPC(Inter-Processor Communications) network.
For an efficient inter-processor communications system based on the IPC network, there are employed nodes at some intermediate points of the IPC network in order to route and arbitrate a data flow between the processors. To each of the nodes, an independent and unique node address is assigned. Whenever the ESS is turned on, an initialization of the node address is required: that is, the assigned address must be stored at an address register residing therein upon turning on the ESS.
In FIG. 1, there is illustrated a conventional node address initialization apparatus which is capable of initializing a single node address. In FIG. 1, the conventional node address initialization apparatus comprises a set of jumper straps 10 and a buffer 11, wherein the number of the jumper straps depends on the word size of the node address and the buffer is connected to the address register residing in each node. One side of each jumper strap is grounded and the other side thereof is connected to the buffer and a voltage source Vcc of, e.g., 5 V, via a pull-up resistor.
If the jumper strap is bridged, 0 V or a logic "0" is inputted to the buffer; otherwise, 5 V or a logic "1" is inputted to the buffer. If the ESS is turned on, a node address word formed by manipulating the jumper straps is stored in the buffer. Then, the node address in the buffer is transferred to the address register 12 at the node. Since the conventional node address initialization apparatus shown in FIG. 1 can initialize only a single node, there are needed as many node address initialization apparatus as the number of nodes involved therein to accomplish the initialization process, thereby making the apparatus complex and costly.
There are other drawbacks in the conventional node address initialization apparatus: for instance, the node address must be manually and individually assigned to every node involved; and, it is difficult to realize a high integrity node board due to the non-electronic nature of the jumper straps; and, furthermore, an alteration of the node addresses cannot be performed while the ESS is in operation.